Re: Canadian Sea Island S

Posted by Laszlo on Dec 31, 2006

Russ,

If I understand what you're saying, you want to piece together long panels from leftover pieces to reduce waste, right?

As far as the butt joints go, if you use a butt block (as in the fore/aft deck joint on the Chesapeakes), you'll get lots of strength but some flattening at the joint. This is OK on that deck joint since the deck is flat there anyway, but at a part of the boat that's supposed to have a strong curve it'll result in an unfair hull.

Taped butt joints are more flexible, but work best in true composite construction. That is, where the wood is only a core used to separate the load-bearing fiberglass skins for increased stiffness. In that case, the glass tape essentially tack welds the joint together until the structural glass layers are applied. I think very few, if any, of CLC's boats are true composite. They're monocoque plywood with fiberglass layers for abrasion protection. (And please, don't anyone interpret that in a derogatory sense - a good boat doesn't have to be composite.) So a taped joint may not work all that well.

The scarfs are probably the best bet. I think the rule of thumb is 8:1 for the length to thickness ratio, so you'd be having to subract close to 2 inches from each piece of wood for every scarf. So a piece scarfed at both ends would lose 4 inches from its length contribution to the finished piece.

While a perfect scarf joint should be as strong and almost as flexible as a single piece of wood, in practice you'd probably want to limit the joints to as few as possible.

Good luck and let us know how it turns out,

Laszlo

In Response to: Re: Canadian Sea Island S by Russ Hall on Dec 31, 2006

Replies:

• Re: Canadian Sea Island S by Jim E on Dec 31, 2006